The present invention relates to an improved fuse for transmitting a detonation signal to a fuse device and to an improved method for producing such fuses.
The fuses of the general type to which the present invention pertain are known in the art as shown by U.S. Pat. No. 3,590,739 issued to Per-Anders Persson and assigned to Nitro Nobel AB, of Gyttorp, Sweden. The Persson patent is a pioneer invention disclosing a hollow elongated tube forming a gas channel which has a reactive substance distributed as a thin layer on the inner surface of the tube for propagating a percussion wave or detonation wave from one end of the tube to the other and describes a fuse generally formed from an extruded plastic material (such as soft polyvinyl chloride). The inner surface of the tube is coated with a suitable reactive substance including such explosives as PETN, RDX, HMX, TNT or mixtures thereof.
U.S. Pat. No. 4,328,753 issued to Leif Kristensen et al and assigned to the same assignee as the aforementioned Persson patent discloses a fuse having an inner plastic tube (formed of material such as Surlyn 1855, a registered trademark of E. I. du Pont de Nemours & Co. Incorporated) whose inner surface is coated with an explosive or suitable reactive material, the inner plastic tube being covered by an inner plastic tube intended to enhance certain mechanical characteristics of the invention while retaining the basic Persson patent concept of utilizing a plastic tube having the reactive material distributed along its length.
Such fuses have been commercially accepted and successful, finding wide usage in a variety of environments for initiating explosives, as for example, where electrical detonation is unacceptable because of environmental hazards.